Other

Good to know:
A Dynamic Survey of Graph Labeling
MathWorld – the web`s most extensive mathematics resource
 
Good to use:
 
Good to read:
something from the polish fantasy writer – Andrzej Sapkowski
 
Good to see:
to know how beautiful the Earth is – Earth Science Picture of the Day
to know how beautiful the Universe is – Astronomy Picture of the Day
 
Good to hear:
 
Good to visit:
Science center NEMO
very nice castle Kaastel de Haar